The present invention relates to a charge mode active pixel sensor read-out circuit.
Image sensors can be applied in a wide variety of fields, including machine vision, robotics, guidance and navigation, automotive applications, and consumer products. They can include on-chip circuitry that controls image sensor operation, signal read-out and image processing functions. Image sensors can utilize, for example, active pixel sensor (APS) technology with each active pixel sensor including one or more active transistors. Each pixel sensor element can provide an output value that represents a particular portion of an image. The pixel sensor elements can be arranged as an array. Each element in the array may be read sequentially, one element at a time, by a charge mode read-out circuit.
Parasitic capacitance on a readout bus can detrimentally affect APS charge mode read-out circuit operation. Such detrimental effects may include, for example, increased power requirements, increased noise levels and increased signal settling times with consequential slower system operating speed.